Nato supreme commander General Wesley Clark is not being allowed to fade away quietly. Days after the Clinton administration relieved him of his command two months early, Newsweek is reporting that the victor of Kosovo was blocked from sending paratroopers to Pristina airport to pre-empt an unexpected Russian advance.

Lieutenant-general Sir Michael Jackson overruled General Clark because the British commander did not want to spark a clash with the Russians.

"I'm not going to start Third World War for you," General Jackson told the US commander, according to Newsweek. In the hours that followed General Clark's order, both men sought political backing for their position, but only General Jackson received it.

News of the clash between the British and US commanders comes just days after the US snubbed General Clark by ordering him to step down next year, two months early, to make way for Air Force General Joseph Ralston, vice chairman of the joint chiefs of staff.

The move is widely seen as a rebuke for the man who led Nato to victory, but who clashed repeatedly with his superiors because he favoured more aggressive tactics. General Clark, for example, pressed for the use of Apache attack helicopters, but his wish was denied amid fears of American casualties.

Trouble flared between the two men as soon as General Jackson was appointed commander on the ground in Kosovo. Talks on Russia's role had broken down and the American general was so anxious to stop Moscow from stealing a march on the allies, he ordered British and French troops to take the airport.

General Clark then asked fellow American commander Admiral James Ellis, in charge of Nato's Southern Command, to land helicopters on the runways to prevent giant Russian Ilyushin transport coming in. However, Admiral Ellis also refused, saying General Jackson would not like it.

The Russian planes were only prevented from landing after US officials persuaded Hungary to deny them permission to overfly the country. Both generals turned to their political masters for support, but while the British government backed General Jackson's judgment, General Clark received no support, effectively meaning his orders were overruled.

In Kosovo itself, the province took a step towards normality when post office workers and university professors returned to their jobs in the capital Pristina.

Bernard Kouchner, who heads the UN mission in Kosovo, accompanied hundreds of ethnic Albanian workers back to their jobs at the main headquarters building in Pristina.

"This is an important day in the rebuilding of Kosovo," Mr Kouchner told the workers. "It is a very important day because the workers are going back to their work."

But ethnic tension remains high. A bombing yesterday of an Orthodox church in the heart of Kosovo's capital underscored Serb fears that Nato is unable to protect them from vengeful Albanians. The bombing "was not a surprise because for the last few days we have been telling every day the K-For officers that this is going to be the next target," said Father Sava Janjic, a prominent Serbian Orthodox priest in Kosovo.

In Serbia, opponents of Yugoslav President Slobodan Milosevic said they would hold a major rally in the capital on August 19 calling for a transition government to lead the country to democracy.